Firing mechanism for automatic submarine mines.



G QLMATRICA'RDI. I FIRING MECHANISM FOR AUTOMATIC SUBMARINEMINES,

APPLICATION FILED mi. 6, 1911.

Patented Ja 16, 1917.

2 SHEETS-SHEET I karma.

G. MATR'ICARDI. FIRING MECHANISM {0R AUTOMATIC SUBMARINE mugs.

APPLICATION FILED F2316, 19H. 1 12,536 Patented. Jam16,1917.

. 2 SHEETS-SHEET 2- minimum depth of submergence.

manner explosions by sympathy are pract1-' UNITED STATES PATENT OFFICE.

GIUSEPFE MATRICARDI, OF PALLANZA, ITALY, ASSIGNOR T0 SOCIETE HARLE & CIE., OF PARIS, FRANCE, A CORPORATION OF FRANCE.

Specification of Letters Patent.

Patented Jan. 16, 1917.

Application filed February 6, 1911. Serial No. 606,772.

To all whom it may concern.-

Be it known that I, GIUsEPrn MATRIGARDI, of Pallanza, Italy, engineer, have invented a new and useful Improvement in Firing Mechanism for Automatic Submarine Mines, which improvement is fully set-forth in the following specification.

This invention has for its object means for firing automatic submarine mines.

Most of the apparatus at present in use, which have the same object, depend upon the inertia of a movable mass or upon radial rods which act, owing to a shock directly, or through the intermediary of an electric current, upon the detonator of the explosive charge. None of these arrangements possess the advantages of the method hereinafter described which are: 1. Obviating the use of the movable mass and electricity which are dangerous in submarine mines charged with explosives. 2. Rendering the mine absolutely safe if it is drifting and not submerged at a predetermined depth, so that neutral ships have no occasion for anxiety when not in the waters of belligerents. These results are attained according to this invention by the employment of firing mechanism put in action by a leak of water produced at determined points of the 'mine by the effect of the impact of a ship against the mine; the firing mechanism is regulated in such a manner that it can only come into action at a pressure of water corresponding to a predetermined In this cally prevented and also all danger 0 premature explosion when launching and rails; ing the mine.

The action of the mine is dependent on the pressure of the water which surrounds it, and if the mine is not submerged or is 1nsufliciently submerged, its explosion 1s absolutely impossible.

The arrangement preferably consists, according to this invention, of a primer and a percussion hammer acted on by one or more springs, but locked by mechanism released by a member displaced by a. reciprocatory part such as a piston or diaphragm, when the said piston or diaphragm is acted upon by the pressure of the surrounding water caused by a leak of water due to the breaking as the result of an outside shock of the end of a normally closed pipe, con

necting the firing mechanism to the outside of the mine; a safety cock may also be provided which is acted upon by a spring'tending to open it, but is provided outside the mine casing with a soluble pin for retaining it in the closed position.

The accompanying drawings illustrate a mine equipped with firing mechanism in accordance with this invention.

In these drawings Figure 1' represents a vertical central section of the mine; Fig. 2 a detail view of a contact horn and accessory parts; Fig. 3 a partial plan view of the mine; Figs. 4E and 5 horizontal transverse sections of the cock on line A- A, Fig. 1 showing the positions of the same; and Figs-6 and 7 transverse horizontal sections of the hammer on lines B-B' and C-C, re-

spectively in Fig. 1.

' In the upper portlon of the casing 1 of ciently outside the casing of the mine to ini sure that, if the mine is struck, the horn itself comes into contact with the striking body; the horn is then struck directly or only by the rotation of the mine which slides in rotil-ting upon the hull of the striking ship. Each horn'is screwed upon the end of a pipe 3, connected to a cock 4, which has for its object to establish communication, or interrupt it, according to its position, between the tube 3 and a central tube 5. From the central tube 5 starts a flexible tube 6. which opens into the cover 7 of a cylinder 8 forming a closed chamber in which moves a reciprocatory part such as a piston 9 or a flexible diaphragm, such diaphragm being the equivalent of the piston for the purpose of this invention.

It will be noted that the tubes 3, 5 and 6 are air. trapping tubes, and together with the cock 4 they form air trapping means communicating withthe cylinder or chamber 8 in which the piston works.

Below the piston 9 are arranged two springs of which one 10 serves to push the piston upward and the other 11 which serves to act upon the percussion hammer 12 by its compression when the piston 9 is in its lower position. The hammer 12 is formed of acylind'rical mass in which is formed a diametrial recess and a. central socket 12. Its lower portion is provided with a. central point 13 which serves to strike the cap 14.

In the diametrical recess are lodged two symmetrical catches 15, which can rock about their'fulcra 16. Their lower points 17 normally engage in notches 1S and their upper ends are drawn toward each other by alight spring 19, in such a manner that the hammer 12 remains suspended.

In the central socket l2 of the hammer 12 slides the rod 20 of the piston 9 or the diaphragm, whose shape is such that when the piston 9 is in its normal position the lower portion 21 of the said rod locks the two catches 15 and forces them to remain engaged in the notches 18. When the piston falls, the two catches 15 are first unlocked, then their upper ends are separated from each other by the conical portion 22 of the piston 20. In this movement, their lower ends are withdrawn. from the notches 18 and the hammer is then free to yield to the action of the spring 11, the lower ends 1.? of the catches being received in recesses 12*, Fig. 7.

The cock 4 is a safety member. The working lever 4; of the cock is constantly acted upon by a spring 23, which tends to bring it into a position such that communication between the tubes 3 and the cylinder 8 may be established. This arrangement is best represented in Figs. 1 and 5 where it will be seen that the spring 23 is secured at one end to the pipe 3 and at the other to the lever 4 connected to the perforated plug of the cock. The spring 23, by this arrangement tends to draw the lever 4 from the position of Fig. 5 where the cock is closed and the passages 4 are out of communication with the pipes 3, to the open position of Fig. 4, where the communication between the said passages and the pipes 3 is established.

The plug 4, as best seen in Figs. 4 and 5, is formed with the plurality 0t passages l" which communicate with the central passage 4, connected with the tube 6, thereby establishing communication between the pipes 3 and the said tube 6 when the plug occupies the position indicated in Fig. 4.

In any case, by means of the hand lever 24, Figs. 1 and 3, located outside the casing, the cock'can be turned in such a manner as to close communication between the tubes 3 and the cylinder 8 and to maintain it closed by the aid of a pin inserted into the hole 25 in the quadrant 26. If this pin is soluble, the cock will open some minutes after the mine has been submerged. If the pin is of metal, the cock will remain closed and the mine cannot explode, even when submerged. At the end of each tube 3 (Figs. 1 and 2) is screwed a stopper 27, hermetically closing the tube of which one portion 28 is frangible, being in the present example formed of much tainner metal, so that by striking against the upper part of the horn 2, the same may be broken off at the said weakened portion 28. Before launching the mine, a horn 2 is screwed. upon the stopper and when it is desired to take up the mine or when it floats, the horn should be removed. If the stopper 27 breaks at 28, the inside of the tube 3 comes into communication with the surrounding medium. and if the mine is submerged, water passes into the tube 3 and can act or not upon the piston '9 according as the safety cock 4 is open'or closed.

The apparatus works as follows :T he mine being ready for launching, the three horns 2 are screwed on, the safety cock is closed by turning the hand lever 24. It is maintained in the closed position by the aid of a pin soluble in water, placed in the hole 25 (Fig. The mine is then launched. If it anchors itself automatically, it will place itself at a predetermined depth; after some minutes the pin in the hole 25 will be dissolved and the spring 23 will turn the safety cock in a manner such as to open communication between the tubes 3 and the cylinder 8. The mine is now ready to explode on a sufficient shock. If a vessel touching the mine does not at once strike a horn, it will come into contact with the mine itself, which will turn upon itself and each horn at each turn will receive a shock until one of them breaks. At this moment water passes into the air-trapping tubes 3 and 6, compresses the air contained therein and acts by its pressure upon the upper face of the piston 9 which falling will compress the two springs 10 and 11 and the conical portion 22 on the rod 20 will liberate the hammer 12 from the notches 18 and cause the explosion of the charge.

It is to be understood that the described operation occurs only if the mine be submerged to such a depth that the effective hydrostatic head is sullicient to compress the air above piston 9 to such an extent as to overcome the resistance of spring 11. This spring can of course be designed to have a resistance suitable for any given depth of immersion; or the resistance thereof may be capable of variation.

If the mine is to be picked up so soon as it reaches the surface of the water, it should be approached by a small boat, in order that the handle of the safety cock may be turned and fixed in its closed position by a metal pin. Afterward if desired the horns may be unscrewed and then the mine may be handled without difficulty or peril, no danger would be incurred even if, for any reason, it were again to be submerged to a distance normally suflicient to permit of its acting.

' Claims- 1. In a submarine mine, a firing mechanism comprising a reciprocatory part, a detonating hammer and means operated by the reciprocatory part for releasing the hammer,

in combination with a chamber in which the reciprocatory part works, a pipe communicating with the said chamber, and yielding means for preventing a movement of the reciprocatory part before a minimum pressure against the same is attained, a safety cock for preventing water from reaching the chamber, and means for opening the cock after a predetermined period of submersion.

2. In a submarine mine, a firing mechanism comprising a piston, a detonating ha'mmer and means operated by the piston for releasing the hammer, in combination with a closed cylinder in which the piston works, means for trapping air connnunicating with the cylinder, a frangible member closing said pipe and projecting from the mine and yielding means for preventing the movement of the piston before a minimum pressure against the same is attained.

3. In a submarine mine, a firing mechanism comprising-a piston, a. detonating hammer and means operated by the piston for releasing the hammer, in combination with a closed cylinder in which the piston works, an air-trapping pipe con'nnunicating with the cylinder, a frangible member closing said pipe and projecting from the mine and a spring opposing the movement of the piston until a given pressure is exerted thereon.

4. In a submarine mine, a firing mechanism comprising a piston, a det-onating hammerand means operated by the piston for releasing the hammer, in combination with a closed cylinder in which the piston works, a wat r pipe communicating with the cylin- (lor, a frangible member closing said pipe and projecting from the mine, and yielding means for preventing the movement of the piston before a minimum pressure against the same is attained, and a safety cock for preventing water from reaching the cylinder.

In a submarine mine, a chamber, an airtrapping pipe comnmnicating therewith and a horn closing the said pipe and projecting from the mine, in combination with a recip rocatory part arranged in the chamber, the projecting horn being provided with a weal;- ened portion, whereby the rupture and the opening of the pipe to water will be caused by an impact against the horn.

G. In a submar ne mine, having a chamber containing a-det nator, a reciprocatory part ar 'anged within and closing the upper part i of the chamber against admission of fiuid to the portion containing the detonator, and a pipe connecting the upper part of the cham' ber with the outside of the mine, in combi nation with a horn closing said pipe and projecting beyond the mine and having a weakened portion, whereby the rupture of the horn and the opening of the pipe to water will be caused by an impact against the horn.

7 In a submarine mine, a chamber and a detonatoroperating reciproca'tory part adapted to work in the same, in combination with a pipe communicating with the chamber, a plurality of pipes branching from the said pipe, and extending to the exterior of the mine, and a cock arranged at the junction of the pipes and adapted to simultaneously open or cut olf the communication etween the outwardly extending pipes and the inner pipe.

8. In a submarine mine, a cylinder and a detonator-operating piston adapted to work in the same, in combination with a water- DEAN M. MARION, I 13. CoMBs. 

